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03 YZ250F not starting

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I have an 03 250f that just had the motor rebuilt, I put it back in, put all the fluids in, and now I can't get it to start. Any ideas? Thanks!

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double check valves

did u overtighten the cams?

test your spark and give it one to two throttle twists

make sure gas is flowing to the carb

make sure you did your timing right

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i took it to my buddy who did the motor work, he just adjusted the valves. It ran great for 4 rides,and it started to make a clacking noise. I haven't started it since. I drained the oil, and it was clean. Any suggestions? This is my 1st 4 stroke. Thanks guys

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All i know is in the motor. I was sitting in idle, and revved it up in neutral and it started making a continuous clacking noise. sorry I'm not more help. it had plenty of oil, but it wasn't showing on the dipstick.

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All i know is in the motor. I was sitting in idle, and revved it up in neutral and it started making a continuous clacking noise. sorry I'm not more help. it had plenty of oil, but it wasn't showing on the dipstick.

That's a scary statement, how long after you shut the engine down before you checked the dip stick? How much oil was poured into the engine before starting? Was the lower end re-built? Did you prime the oil pump before starting it up the first time?

We need more information to help. Have you opened the valve cover to inspect the cams and timing chain, have you slowly turned the engine over trying to find the clacking?

Good Luck

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you most likely ran it dry. Sounds like the oil never made it to the top end. You did change the filter and oil correct?

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Could be the cam chain tensioner too. Sometimes they will wear out and not hold the chain tight or allow it slip out of time. Once that happens you bend valves. Don't run it until you check what the noise is.

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